Anthranilamide

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: modern guideline study, conducted according to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Anthranilamide

EC Number:

201-851-2

EC Name:

Anthranilamide

Cas Number:

88-68-6

Molecular formula:

C7H8N2O

IUPAC Name:

2-aminobenzamide

Test material form:

other: solid

Details on test material:

Identification: Anthranilamide
Test Item No.: 15/0042-1
Batch: 0005190619
CAS-No.: 88-68-6
Content: w (main component): approx. 100.1 g/100 g Determined by potentiometric titration, for details see analytical report No.: 15L00067
Physical state, appearance: Beige solid
Homogeneity: The test item appeared to be homogeneous
Expiry Date: 19 January 2016
Storage Conditions: (provided by the Sponsor) At room temperature

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

0.1, 0.25, and 0.5% (w/w)

No. of animals per dose:

5 females (nulliparous and non-pregnant)

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.21

Test group / Remarks:

0.5% w/w

Remarks on result:

other: Mean SI (n=5)

Results 2

Parameter:

SI

Value:

1.31

Test group / Remarks:

0.25% w/w

Remarks on result:

other: Mean SI (n=5)

Results 3

Key result

Parameter:

SI

Value:

1.18

Test group / Remarks:

0.1% w/w

Remarks on result:

other: Mean SI (n=5)

Results 4

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: mean DPM (n = 5) 0.1%: 2440.5 +- 858.9 0.25%: 2720.1 +- 513.7 0.5%: 2509.1 +- 483.9

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

The test item Anthranilamide was not a skin sensitizer.

Executive summary:

In order to study a possible skin sensitising potential of Anthranilamide, three groups each of five female mice were treated once daily with the test item at concentrations of 0.1, 0.25, and 0.5% in DMSO by topical application to the dorsum of each ear for three consecutive days. The test item could be dissolved in the vehicle. The appropriateness of the used concentrations was previously assessed by four pre-experiments. A control group of five mice was treated with the vehicle DMSO only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised, pooled per animal and immediately weighed. Furthermore, after excision of the lymph nodes, both ears of the mice were punched at the apical area using a biopsy punch and were immediately weighed pooled per animal using an analytical balance. Afterwards single cell suspensions of lymph node cells were prepared from pooled lymph nodes per animal. An aliquot of each cell suspension was used for determination of lymph node cell count. Subsequently the suspensions were washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a β-scintillation counter. The animals showed neither signs of systemic toxicity nor mortality during the course of the study. From day 3 to 5, the animals treated with 0.25 and 0.5% showed an erythema of the ear skin (score 1). A statistically significant or biologically relevant increase in ear weights was not observed in any treated group in comparison to the vehicle control group. Furthermore, for BALB/c mice, a cut-off value of 1.1 for the ear weight index was reported for a positive response regarding ear skin irritation (see Ref. 9). None of the indices determined for the test item treated groups reached or exceeded this threshold. A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study Stimulation Indices (S.I.) of 1.18, 1.31, and 1.21 were determined with the test item at concentrations of 0.1, 0.25, and 0.5% (w/w) in DMSO, respectively. A statistically significant or biologically relevant increase in DPM value and also in lymph node weight and - cell count was not observed in any treated group in comparison to the vehicle control group. Furthermore, the cut-off value of 1.55 for a positive response regarding the lymph node cell count index reported for BALB/c mice (see Ref. 8) was not reached or exceeded in any dose group. The EC3 value could not be calculated, since none of the tested concentrations induced a S.I. greater than the threshold value of 3.